An Introduction of ensemble prediction scheme of China Meteorological Administration Climate Prediction System version 3

Ensemble prediction has been an important tool for weather forecast, sub-seasonal to seasonal prediction, seasonal prediction, interannual prediction and even simulation of climate change. The role of ensemble prediction has received widespread attention in the field of meteorology. This paper introduces the ensemble prediction scheme of the Climate Prediction Operational System version 3 of the China Meteorological Administration (CMA-CPSv3). In this scheme, we adopted a way of combining the physical process tendency stochastic perturbation in atmosphere, the air-sea flux stochastic perturbation and the time-lagged initial value perturbation. Based upon the version 2 of High-Resolution Beijing Climate Center Climate System Model (BCC-CSM2-HR), we developed and constructed a multi-layer random perturbation ensemble prediction system with relatively good ensemble sample dispersion, stability, and reliability. The evaluation results of the hindcasts in the past 20 years show that this ensemble prediction system has a significant improvement in the prediction of summer precipitation, 2m temperature over China, El Niño-Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and Asian monsoon, especially the random perturbation of air-sea flux shows a positive effect on the improvement of ENSO and South Asian Monsoon (SEAM) and Western North Pacific Summer Monsoon (WNPSM) indices prediction skills.